1. Field of the Invention
The present invention relates to a plug making machine for forming a plug and a cord protector integrally at one end of an electric cord and, more particularly, to a cord tension device for use in the plug making machine of the type stated above.
2. Description of the Prior Art
A considerably large bending stress is generated at the junction between a flexible electric cord and a solid mold plug and the life of the electric wire in the cord becomes short due to the generation of such stress. Under these circumstances, there have been proposed a variety of cords having a cord protector at the portion of the cord subjected to the bending stress to protect the cord against breakage. In these electric cords, the cord protector is formed integrally with the plug at one end of the cord. In order that the cord protector provides the expected protection effect, it is essential that the cord protector is formed on the cord surface with a uniform circumferential thickness distribution. For obtaining such a uniform thickness distribution of the cord protector, it is necessary to apply a tension to the cord after placing one end of the latter in the mold cavity, so that the cord may be set in a tensed state correctly on the axis of the cavity during molding. This setting of the cord has been made heretofore wholly manually by pulling the cord away from the mold by operator's hand. This work is very troublesome and the positioning of the cord correctly on the cavity axis is extremely difficult to conduct.